Question

The circumference of a circle is 123.2 cm. Taking $\pi =\frac{22}{7}$, calculate the radius of the circle in cm is

• A. 28 cm
• B. 19.6 cm
• C. 5.6 cm
• D. 11 cm

Answer 1

The correct option is B 19.6 cm

$Given-thecircumferenceCofacircle=r=123.2cm.Tofindout-theradiusofthecircle=?$

$Solution-ThecircumferenceCofthecircle=2\pi r$
$\Rightarrow r=\frac{C}{2\pi }=\frac{123.2}{2\times \frac{22}{7}}cm=\frac{123.2\times 7}{2\times 22}cm=19.6cm.$

$Sotheradiusofthecircle=19.6cmAns-OptionB.$